Tap-driving head.



No. s7|,447.

Patented Apr. 9, l90l. R. L. MORGAN &. D. D. WILLIAMS.

TAP DRIVING HEAD.

(Application filed July 12, 1898.

2 Sheets-Sheet I.

(No Model.)

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Nu. 67!,447. ,Patented Apr. 9, l90l. R. L. MORGAN & D. D. WILLIAMS.

TAP DRIVING HEAD.

(Application filed Juiy 12, 189B.)

2 Sheets-Sheet 2.

(No Model.)

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RALPH L. MORGAN AND DAVID D'. WILLIAMS, OF WORCESTER, MASSA- CHUSETTS; SAID WILLIAMS ASSIGNOR TO SAID MORGAN.

TAP-DRIVING HEAD.

SPECIFICATION forming part of Letters Patent No. 671,447, dated April 9, 1901.

Application filed July 12,1898. Serial No. 685.74=9. (No model.)

To all whom it may concern.-

Be it known that we, RALPH L. MORGAN and DAVID D. WILLIAMS, citizens of the United States, residing in Worcester, in the county of Worcester and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Tap-Driving Heads, of which the following is a specification, accompanied by drawings forming a part of the same, in whicl1- Figure 1 represents a view of our improved tap-driving head with the tap held therein. Fig. 2 is a central vertical sectional viewon line 22, Fig. 1. Fig. 3isavertical central sectional view on a plane at right angles to that shown in Fig. 2. Fig. 4 is a central sectional view of the head, showing the position of the tap rotating mechanism during the operation of tapping. Fig. 5 is a central sectional view of the head, showing the position of the taprotating mechanism when the tap is released. Fig. 6 is a central sectional view of the head, showing the operation of the device when reversing and withdrawing the tap.

Similar letters refer to similar parts in the different figures.

Our present invention relates to a tap-hea for holding a screw-tap, comprising mechanism by which the rotation of the head is communicaled to the tap in the operation of cutting a screw-thread, mechanism forautomatically disengaging the tap from the rotating head as the end of the tap approaches the bottom of the hole to be tapped, and mechan-' ism for reengaging the tap as the rotation of the head is reversed and the head is raised for the purpose of withdrawing the tap; and it consists in the construction and arrangement of parts, as hereinafter described, and set forth in the annexed claims.

Referring to the drawings, A denotes the tap-head, provided with atapering shank A, adapted to be inserted in and rotated by the hollow revolving spindle of a lathe or drillpress, by which the tap-head can berotated and advanced or Withdrawn by means of the usual and well-known feeding mechanism connected with the spindles of lathes and drill-presses. The end of the tap-head A is provided with a central circular chamber forming a socket A adapted to receive the the socket A cylindrical shank B of a tap B. Extending upward from the socket A is a central circular chamber A The tap-head A is provided with a diametrical mortise C, with its upper portion passing through the chamber A and with its lower portion passing through The mortise G contains a flat steel key or driving-bar O, which is somewhat narrower than the mortise O, leaving a space G which allows a slight'sliding motion of the driving-bar O in the tap-head A. The central chamber A contains a spiral com pression-spring D, which presses against the end wall D of the chamber A and a disk D, held in a notch C in the upper edge of the drivingbar C, so that the pressure of the spiral spring D will push the driving-barO against the lower end wall of the mortise O.

The shank B of the tap is provided with a groove E in its upper end to receive the edge of the driving-bar 0 when the shank is inserted in the cylindrical socket of the taphead, causing the rotation of the tap-head A to be communicated to the tap B.

The tap is provided with a concentric hole E to receive a sliding spindle F, which projects beyond the end of the tap at F.

The upper end of the shank B is count-erbored in the bottom of the groove E to receive the head F of the sliding spindle F. The shank B is provided about midway its length with a'circumferential groove G, which receives the point of a screw G, held in the taphead, and holds the tap from falling out when used in an upright drill-press. Upon the upper side of the groove G is a notch G having a vertical abutting wall G so that when the tap is held in the tapped hole the point of the screw G will be drawn into the notch G by raising or withdrawing the tap-head, causing the point of the screw to strike against the wall G3 when the tap-head is reversed, and thereby reversing the tap for the purpose of withdrawing it from the tapped hole.

The operation of our improved tap-head in the operation of tapping, releasing the tap, and withdrawing it from the tapped hole is as follows: The rotation of the tap-head A is imparted to the tap by means of the driving.

bar 0, which is held in the mortise O and is pressed into the groove E in the end of the tapped shank B by the spiral compression.- spring D, forming a clutch between the taphead and the cylindrical shank B of the tap. When the tapping is completed, the projecting end F of the sliding spindle F is brought in contact with the bottom of the hole, which pushes the spindle F into the tap and lifts the driving-bar 0' against the pressure of the spring D, thereby removing it from the groove E in the shank B and releasing the tap. The rotation of the tap-head is then reversed and raised slightly, bringing the end of the screw G into the notch G and against the Wall G causing the tap to be rotated backward and withdrawn from the work.

What we claim as our invention, and desire to,v secure by Letters Patent, is

1. The combination with a tap-head pro-I vided with a socket adapted to receive a tap, a tap provided with a diametrical groove in the end of its shank, said tap-head havinga mortise entering said socket and overlapping the grooved end of a tap-shank inserted therein, of a driving-bar held in said mortise and arranged to engage the grooved shank of the tap and capable of sliding in said mortise lengthwise the tap-head, a spring bearing against said driving-bar to hold it in engagesliding spindle, asliding spindle held in said tap and projecting from its end, said spindle bearing against said driving-bar and a spring applied to said driving-bar to hold it in engagement with the tap, substantially as de-; scribed. t

3. The combination of a tap-head provided with acircular socket for a tap, a tap having a cylindrical shank held in said socket and provided witha circumferential groove, a pin or screw held in said tap-head with its end entering said groove whereby the tap is held from withdrawal by one of the side walls of said groove, said groove having a notch inchamber A and adiametrical mortise C, of a taphaving a cylindrical. shank B, provided with a transverse groove E in its end, a driving-bar 0 held in said mortise and having a notch C a disk D held in said notch and a compression-spring D held in the'chamber A with its tension applied to said disk to hold the driving-bar O in the groove E of the tap, substantially as described.

5. The combination with the tap-head and tap held therein and provided with a grooved shank of the driving-bar held in said tap-head and engaging the grooved shank of said tap, a spring with its tension applied to hold said driving-bar in engagement with said tap and means for automatically pushing said driving-bar outof engagement with said tap when theoperation of tapping has been completed,

substantially as described.

6. The combination with a rotating taphead provided with a socket to receive a tapshank, a driving-bar held by said tap-head and projecting into the tap-socket, a tap having a shank fitting said socket and engaged by said driving-bar and means for automatically disengaging said driving-bar from the tap-shank, substantially as described.

Dated this 6th day of July, 1898.

RALPH L. MORGAN. DAVID D. WILLIAMS. 

